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Presented at ICAO ACP WGC Meeting,

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1 Presented at ICAO ACP WGC Meeting,
FCS Technology Assessment Team: Technology Assessment Phase II – P34 Overview Presented at ICAO ACP WGC Meeting, Brussels, Belgium September 21, 2006 Prepared by: ITT/Glen Dyer NASA/James Budinger

2 Public Safety Radio Systems
Standardized systems with open interfaces APCO Standards Developed by TR-8 Private Radio Technical Standards Committee, under sponsorship of the TIA in accord with a memorandum of understanding between TIA and APCO/NASTD/FED (Association of Public Safely Communications Officials/National Association of State Telecommunications Directors/Federal Government). TETRA Standards Produced by the Project Terrestrial Trunked Radio (TETRA) Technical Body of the European Telecommunications Standards Institute (ETSI) TETRAPOL Development of the publicly available specifications for TETRAPOL has been carried out by the manufacturers of the TETRAPOL Forum and the TETRAPOL Users’ Club IDRA Standardized by the Association of Radio Industries and Businesses (ARIB). The first version of Japan's digital dispatch standard, called RCR STD-32, was completed in March 1993. An updated version of this standard which did not alter the basic RF characteristics of the standard, but which did add substantial networking capability to the system, was approved in November 1995, and is referred to as RCR STD-32A. Commercial spectrally efficient land mobile radio systems Integrated Digital Enhanced Network (iDEN™) (referred to internationally as DIMRS) – Proprietary Motorola narrow-band TDMA voice and data system EDACS (Enhanced Digital Access Communications System) – Proprietary Ericsson trunked narrow-band fail-soft system for critical communications

3 Public Safety Radio Standards Segmentation
Project Mesa Bit Rate APCO 34 Tetra Release 2 (TAPS, TEDS) 1000’s kbps Broadband 100’s kbps Wideband 10’s kbps Narrow band Channel Widths 6.25 kHz 25 kHz 50 kHz 200 kHz 25 MHz APCO P25 Phase 1, 2 Tetra Release 1 TETRAPOL IDRA iDEN EDACS Chart courtesy of EADS Defense and Communications Systems, as provided in correspondence between ITT and EADS

4 Evolution of Public Safety Radio Standards
Pre-standard Analog, 25 kHz FM European Standards Evolution Pre-standard Analog FM Systems Narrowband Tetra Release I 25 kHz 4-slot TDMA UHF Band Wideband Tetra Release II TAPS – E-GPRS Overlay Network TEDS – MCM, TDMA, Adaptive Modulation, 150 kHz Solution Space* US Standards Evolution APCO Project 16 Study APCO Project 34 OFDM 150 kHz Channels 700 MHz Band APCO Project 25 Phase I 12.5 kHz Digital VHF and UHF Bands APCO Project 25 Phase II 12.5 kHz TDMA *Solution space - The set of technologies for constructing a public safety network. Broadband Project Mesa 50 MHz channel at 4.9 GHz (Joint ETSI and EIA/TIA Standard)

5 P34 Overview APCO Project 34 is a EIA/TIA standardized system for provision of packet data services in an interoperable dispatch oriented topology for public safety service providers Standards available here: Example standard description TIA-902.BAAB - Complete Document Revision: A    Chg:    Date: 09/23/03   WIDEBAND AIR INTERFACE SCALABLE ADAPTIVE MODULATION (SAM) PHYSICALLAYER SPECIFICATION - PUBLIC SAFETY WIDEBAND DATA STANDARDS PROJECT - DIGITAL RADIO TECHNICAL STANDARDS Project 34 concept is a government/commercial partnership Provides universal access to all subscribers Carefully controlled and managed network Was developed to address “issues that restrict the use of commercial services for mission critical public safety wireless applications” Priority access and system restoration Reliability Ubiquitous coverage Security

6 P34 Overview (2) A P34 network (called a “Wideband System”) can interoperate with other P34 networks (the ISSI standardized interface) with end-systems (Ew interface) and with mobile users over the air interface (Uw) The air interface has defined modes between mobiles (MR to MR); between mobiles and fixed infrastructure (MR to FNE) and repeated modes for extending range to distant stations Mobile Radios can serve as repeaters to extend range from FNE to distant Mobile Radios The protocol stack is layered, and assumes a point of attachment to an IP network

7 P34 Overview (3) P34 systems (shown as TIA-902 in the figure) are slated to be deployed using Frequency Division Duplexing with Forward Link (Fixed Network Equipment, FNE, to Mobile Radios, MRC) between 767 and 773 MHz as shown in the figure Reverse Link (MRC to FNE) between 797 and 803 MHz The band could be cleared in some areas by December 31, 2006 Provided at least 85% of households have digital capable TV sets Most likely date is (hard requirement) January 2009

8 Wideband (P34) Data Standards Status

9 P34 Air Interface (PHY) Description
There are two air interfaces (PHY) defined SAM for interoperability Has random access burst structure that incorporates 625 s propagation guard time (187.5 km) and s ramp-down (not included in guard) VDL 3 guard time includes the ramp-down time and is 1.14 ms (334 km) Random access burst structure rules could be modified to significantly increase system range IOTA to provide additional data capacity Has random access burst structure that incorporates 500 s propagation guard time (150.0 km) and 500 s ramp-down MAC uses timing advance to offset mobile propagation delays From the standard: “A timing advance feature managed by the MAC layer assumes that propagation delays are not seen at the radio receiver level except for initial random access slot”

10 Air Interface Specifics
Both Air Interfaces use a form of Multi-Carrier Modulation (Orthogonal Frequency Division Multiplexing, OFDM) Frequency Domain Extensibility Base channel is 50 kHz, with extensions defined to 100 kHz and 150 kHz Each 50 kHz segment is comprised of 8 subcarriers (that map to defined subchannels) Concatenate subchannel sync/pilot/data structure of the 50 kHz slot two, three times Simplifies receiver design Completely scalable to much larger bandwidths (if needed) Each 50 kHz provides 96 to 288 kbps (modulation adapts with Eb/No)

11 Scaleable Adaptive Modulation Parameters
50 kHz Channel Configuration 100 kHz Channel Configuration 150 kHz Channel Configuration RF Subchannels 8 16 24 Subchannel Spacing 5.4 kHz Symbol Rate 4.8 k Symbol Filter Root Raised Cosine ( = 0.2) Modulation Type 1 QPSK (2 bits/symbol) Modulation Type 2 16QAM (4 bits/symbol) Modulation Type 3 64QAM (6 bits/symbol) Modulation Rate 1 76.8 kbps 153.6 kbps 230.4 kbps Modulation Rate 2 307.2 kbps 460.8 kbps Modulation Rate 3 691.2 kbps Demodulation Coherent (Pilot Symbol Assisted) TDM Slot Time 10 ms Slot Interleave Variable

12 Inbound Random Access Frame Structure

13 P34 Air Interface Interactions
IP Bearer Service Access Point IP Bearer Service Access Point IPv4 IPv6 IPv4 IPv6 Layer 3 Subnetwork Dependent Convergence Protocol (SNDCP) Subnetwork Dependent Convergence Protocol (SNDCP) Layer 3 PDP context activation, LLC UP setup, data transfer PDS MM PDS MM CP functions: acknowledgement, retransmission, optional enhanced error detection UP functions: Segmentation/Reassembly, acknowledgments, selective retransmission, enhanced error detection, flow control, windowing, buffering Logical Link Control (LLC) Logical Link Control (LLC) Radio Link Adaptation (RLA) Radio Link Adaptation (RLA) Layer 2 Dynamic selection of modulation, channel coding, logical channel multiplexing configuration Layer 2 Media Access Control (MAC) Synchronization, scrambling, link management, random access procedure, MAC address allocation, radio resource allocation, power control Media Access Control (MAC) PHY PHY Layer 1 Layer 1

14 SNDCP Context Activation Sequence Diagram

15 UP Acknowledged Data Transmission Sequence Diagram

16 Overview of P34 Modeling P34 Analysis conducted
OPNET Modeling – the P34 protocol stack was modeled using OPNET Modeler High fidelity simulation of protocol stack provided insight into technology performance Offered load and scenario as specified in COCR for NAS “Super Sector” Physical Layer Modeling – P34 physical layer was modeled with high fidelity by developing a custom C code application Provided insight into technology performance in aviation environment For performance assessment, C was chosen over SPW and MATLAB Simulink® due to complexity of P34 pilot structure Interference Modeling – a model of the P34 transmitter was developed using SPW to assess P34 interference to UAT and Mode‑S Receivers DME receiver modeling was undertaken, but was eventually terminated due to lack of “as built” algorithm information and insufficient fidelity with predictions to known results

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